feat: cleanup code (which probably does nothing but I am hopeful anyway)

src/index.ts

@@ -1,4 +1,5 @@
 import { Client, GatewayIntentBits } from 'discord.js';
+import cleanup, { EXIT_EVENT_NAMES } from './behaviors/cleanup.js';
 import guildMemberAdd from './behaviors/guildMemberAdd.js';
 import interactionCreate from './behaviors/interactionCreate.js';
 import ready from './behaviors/ready.js';
@@ -15,3 +16,7 @@ client.on('ready', ready);
 client.on('guildMemberAdd', guildMemberAdd);
 client.on('interactionCreate', interactionCreate);
 client.login(process.env.DISCORD_TOKEN);
+
+EXIT_EVENT_NAMES.forEach((exitEventName) =>
+  process.on(exitEventName, () => cleanup(client)),
+);